Optical devices have widely spread, and an optical element that controls light has often been used in, for example, a liquid crystal projector, a display, an optical pickup, an optical sensor and others. Also, as these devices have been highly functional, the optical element has been required to be highly functional, high-value added, and lower in cost.
Here, Patent Document 1 and Non-Patent Document 1 describe techniques relating to a wire-grid element having a metal wire structure on a transparent substrate.